Capcom World/Setting

The universe from Capcom World has every single game released by Capcom existing at the same time, being a fusion of multiple universes.

There actually are several universes, but which one is to be the one the game mainly takes place?

Capcom World, the setting from Adventure Quiz: Capcom World (and its sequel), Street Fighter X All Capcom, and Minna to Capcom All-Stars. The games always existed together and expands as new games are released.

Capconia (Puzzle & Dragons)

A world that exists due to the main villain from the game somehow messing with time and space in a similar way to Namco X Capcom, either due to anomalies, time portals, or other means.

A world that exists due to the main villain from the game somehow messing with time and space in a similar way to Marvel vs. Capcom: Infinite, merging different worlds and times. This results in the possible outcomes:

The worlds are separated in the ending.

The worlds are permanently merged, creating a new world with several anomalies/time portals/paradoxes that must be solved.

The convergence is permanent, creating a new world with a new timeline.

Different worlds and times that were forcibly merged in a similar way to the Worlds Unite crossover from the Mega Man and Sonic comics and the planet created by Beyonder in Marvel's Secret Wars.

Other

Alternatively, to reduce the amount of worlds, it can be assumed that at the very least only 1-3 worlds existed before the convergence, similar to Namco X Capcom and Project X Zone, or a single world with the games set in different times, with only time being changed. This would result in similar worlds that are know to be from different universes being put together, like the original Mega Man series and the Mega Man Battle Network series.

In case more than one world is used, the primary world is basically the same as the real world up to 20XX, but with fictional elements such as more advanced technology, powerful martial arts, supernatural beings, time travel, ...

Note: In the Capcom World, Drs. Thomas Light and Tadashi Hikari are cousins instead of different versions of the same person. Both became successful scientists. There is only one Wily and Cossack. Wily's MMBN counterpart appearance is a disguise like "Mr. X" and a robotic copy. MMBN happens before classic, Cossack's MMBN version being his younger self. Wily studied with Light, and later worked alongside Hikari.